1. Field of the Invention
The present invention relates to a control system for an electric vehicle provided with an inverter for converting DC electric power of a main battery into AC electric power to drive a traveling motor.
2. Description of the Prior Art
In prior art electric vehicle control systems, a large-capacity electrolytic capacitor is provided between the terminals at the input side of the inverter of an electric vehicle in order to stabilize the operation of the inverter by smoothing the fluctuation of voltage. It is necessary to discharge the electric charge stored in the capacitor when stopping the traveling of the electric vehicle. Conventionally, discharge of the capacitor has been made by converting the electric charge into heat by means of a resistor provided in the discharge circuit (for example, see Japanese Patent Application No. 6-161535).
However, it is a wasteful use of electric power to abandon the electric charge of the large-capacity capacitor in the form of heat and moreover, a problem occurs because the discharge time increases in order to avoid sudden heat generation by the resistor.